Make Your yahoo messenger multi login in some steps
click start button,then run or press Window logo + R
and then type regedit in Run window and Enter

HKEY_CURRENT_ USER
-Software
—yahoo
—–pager
——Test.
then right click and click on dword or dword32

After click on dword value

and name it as plural

and its value as 00000001 .
and click ok
close your registry window.
Now your yahoo messenger change in multi login.
open and enjoy.